I had commented out that section, but the code kept hanging. I will try reducing to 1 or 0 so the code is still executing (but essentially useless) and see what difference that makes.

And yes, I do Folding@Home. As I said, this is not an actual attempt at a +28 char vanity address generation - it won't be running more than 24 hours. I was simply asking for info on how to modify the code.

samr7 when are you going to fix the bug with the -X switch? if i want to create an address for an altcoin and specify the version with -X vanitygen says something like this (just an example)

Thanks i gave up though. The gpu is actually pretty good on these ivy bridges. Unless vanity also requires amd like bitcoin, then yeah

Catalyst 11.11 should do the trick

Can the latest version (v0.22) make compressed keys? The ones that start with Letters and not 5 for the private key part. Sure I can convert it, but I'd want to generate a few hundred compressed keys (offline) for cold storage.

I haven't read this entire thread, as it's simply too long to read.

Anyway - I decided to store some coins locally, and I decided the safest way would be to run VanityGen and produce adresses along with private keys on an air-gapped computer.

I have a 150MB ISO-image (grml64-small_2013.02.iso) that I've modified with WinISO to add a directory containing these files:

libcrypto.so.0.9.8
libpcre.so.3
readme.txt
vanitygen

Vanitygen is compiled with the instructions in the first post in this thread, from source.

readme.txt simply states:


This makes sure vanitygen searches in the current directory for libraries.

Now, simply run:


to find adresses containing '1mono'-prefix. Or choose any other prefix you'd like, but remember it should start with 1 (or at least so I think).

You will now get the bitcoin address and it's corresponding private key. All what you need now is to note down that key and address, whenever you feel like saving something to that address, just send some coins there. Whenever you want to redeem the coins, import the private key to your wallet. There's many guides for this, so I won't repeat that.

The files, after you've booted can be found inlib/live/mount/medium/vanitygen if you used WinISO (On Windows 7) to put it in the root of the iso-image.

To prepare the USB disk (make it bootable and add iso), I used Universal USB Installer 1.9.3.0. (On windows 7)

Following these instructions, you should be able to create your own bootable vanitygen usb-stick, if you can't be arsed to do it, let me know, in this thread or on pm, and I'll make the iso available if there's any demand for it.

The reason it's safe to do this is that you run it on a machine with no network connection. Make sure to unplug the network cable, or disable the wifi. Then, when the address and private key is generated, once the machine is shut down, there's no trace left of your key, apart from what you have noted down.

Note that printing it with a printer, or taking a picture of the code with your telephone may expose you to other kind of attacks.

Air-gapped, live bootable USB seems very secure. Then check the balance with blockchain.info or any other block explorer site.

Consider:
-Your windows machine is completely PwnD, making any code that touched it untrustable and/or
-Your adversary can remotely access or physically steal the USB device and recover anything you've deleted or had in RAM (swap file).

Better still would be to disconnect all hard drives and storage media on the target machine, and only boot and run off a live CD with a compile environment. You then only have to figure out how to get vanitygen code to the machine securely (removable non-writable media), and how to get the address/privkeys off the machine securely (print, burn CD) without creating any persistent digital copy whatsoever.

If you don't actually need vanity addresses, easier is just to use the bitaddress HTML/JavaScript generator code offline.

Some rand generators use this method to obtain entropy data, but that doesn't do anything by itself.

Vanitygen uses OpenSSL to generate it's random private keys, which is pretty well vetted. If you have concerns that the startup state may be deterministic, you can use something like gpg key generator which does use random keyboard input to increase entropy, and then feed the gpg key data into vanitygen as a random seed.

There are rare hardware platforms that include a real hardware random number generator, notably VIA C3 processors and Intel 840 chipsets. These can feed urandom true hardware randomness with a kernel patch.

extra credit: spot the bitcoin developer
https://www.kernel.org/doc/Documentation/hw_random.txt

Can't the compressed key be derived from WIF?